Snowden: Facebook, Google 'misleading' in denials about surveillance program

While tech companies must maintain their silence about the surveillance program and comply with the government's requests for information, Snowden said they also have an "ethical obligation" to band together and refuse to cooperate with the government.

"If for example Facebook, Google, Microsoft, and Apple refused to provide this cooperation with the Intelligence Community, what do you think the government would do? Shut them down?" Snowden asked.

Facebook, Google, Apple and other major tech companies have vehemently denied that they have been a part of a program that gives the U.S. government "direct access" to its servers. They have also maintained that they first learned about PRISM from recent media reports about the program.

Apple, Facebook and Microsoft have released data about the number of government requests for user information they have received in the wake of the reports. The companies have pressed the government to give them permission to disclose this data in an effort to restore consumer confidence in their handling of people's personal information.

Google already discloses the number of government requests for user information it receives in its "Transparency Report." The report also provides disaggregated information on the type of request Google receives from the government, providing numbers for national security letters separately from criminal ones.

In recent statements, tech companies have also said they thoroughly review each government request for user information and, in some cases, decide not to fulfill them.

Following the revelations about the NSA's surveillance programs, questions have been raised about how "direct access" is defined and whether tech companies are being truthful about not participating in PRISM.

When asked to describe what direct access means during the Q&A, Snowden said "more detail on how direct NSA's accesses are is coming." He also said the NSA can obtain the content of people's communications and keep a record of it.

"If I target for example an email address, for example under FAA 702, and that email address sent something to you, Joe America, the analyst gets it. All of it. IPs, raw data, content, headers, attachments, everything," Snowden said. "And it gets saved for a very long time — and can be extended further with waivers rather than warrants."